semiotec has a good point, but the exception falls under the category of descriptive grammar (what people actually use and understand in conversation) rather than prescriptive grammar (the written and academic rules). You are wanting to know the prescriptive rule, which scyllacat gave.

"Whom are you" is worse than overcorrection. It is simply wrong. In most of its meanings, the verb "to be" does not take an object but a predicate nominative, and therefore nominative rather than objective case.

This is the old rule; the new one seems to be to use the nominative before the verb and objective after it, regardless of the Latin rules. Hence, "It is I" is no longer preferred over "It is me."

@Anonymous: "Where doth thou goest ?" is completely off key.It should be, were one to express oneself in such antiquated verbiage, "Where dost thou go ?"

@semiotek: the "it is I", "It's me" debate is a question of usage and context. The use in French of stressed personal pronoun "moi" in this construction ( "C'est moi" ) may well be at the origin of the "me" in English in this phrase.

I, for one, find nothing wrong with correct grammar. While "who" is often substituted for "whom" , it doesn't cost anything to say or write the correct form.

I remember seeing a t-shirt imprinted with the quote"It's not who you know,it's whom you know."

"Who is it?" is correct, while "It is I whom you seek" is also correct, not "it is I who you seek". Whom always comes before the subject of the sentence ('you' in this case). But nowadays in cases where 'whom' would be correct, 'who' is also accepted.

'Who will we donate money to?''It is you whom we will donate money to' OR 'It is you to whom we will donate money.' You know 'we' is the subject because it can be rearranged to 'We will donate money to you'.

Although you might find it stilted, 'whom does the new tax proposal really benefit' is correct. If we change the interrogative into the declarative (with emphatic verb form): 'the new tax proposal really does benefit whom (us/them/him/her/it/you).' or plainly keep the form and place the objective pronoun by its verb: 'does the new tax proposal really benefit us?'

However, don't clearly chop me down as a prescriptivist; I just prefer reasonable correctness. I am opposed to that antiquated rule of not splitting an infinitive and leaving a dangling preposition, for I see the English language as separate from Latin.

@Jasper - I know the - 'if it's him, it must be whom test' - the only problem is that it is totally out of touch with reality. Yes, 'Whom does the new tax proposal really benefit' is correct in formal grammar, but very few people talk like that. What I don't accept is that in normal informal conversation we are bound by the rules of formal grammar. Or that something which sounds unnatural should be considered more 'correct' than something that sounds natural.

I teach English to foreigners and it is absolutely standard in course books to say that 'whom' is regarded as very formal, and is usually avoided by native speakers. We teach that the only time it's necessary to use 'whom' it is after a preposition. And you can often avoid the problem altogether by stranding the preposition. Current EFL books would not teach 'Whom does the new tax proposal really benefit', but 'Who ...'. So it really depends on your definition of correct. You can read more of my take on his here:

Pronouns are the biggest area of change in English because they are the only vestiges left of the case system which English has largely dumped. This is an ongoing process. Most of us say 'it's me' rather than 'it's I', 'he's bigger than me', not he's bigger than I', but there are people out there who insist the vast majority of us are incorrect. What is a language? A method of communicating effectively in a natural way or a set of hidebound rules, many of which turn out to be the results of some grammarian or other's whim in the 18th or 19th century.

I apologize for acting a little contentious and acerbic. I completely agree that in speech rules like who/whom don't matter. And I wouldn't say "It is me" and "He is bigger than me" are wrong at all. I however feel that we should at least keep whom alive in writing, and if someone wants to adhere to the ellipsis in "He is bigger than I (am)" and the subjective complement "It is I", fine.

I do know that Anglo-Saxon/Old English was inflectional and that the pronouns are the only thing that remains.

@Jasper - No need to aplogise. I think in the end it comes down to personal choice. If people want to use 'whom', in places where it's not necessary that's fine by me, even if it sounds unnatural to many of us, which I would say for 'whom' not preceded by a preposition. In an article in the Telegraph for example, the style editor used 'whom' three times in defining relative clauses, where we normally drop the pronoun altogether - I can't remember the examples but can you imagine a song called 'The man whom I love'? And I'll never use it at the beginning of a question - even though some people seem to think Bo Diddley and The Doors should have sung 'Whom do you love?'.

No, if people want to use these, and don't mind sounding a bit pompous, that's fine by me. But when they start parroting some half-understood rule which is probably only used because it started as somebody's whim, and they call my English incorrect, or people like me ignorant, that get's my goat. Before preaching what others should do, I just wish they'd go and read up some experts on how language actually works and how the majority of educated people speak. Rant over.

When I was younger, I used to say things like:"It's me!""Whom are you?""It's her!""Whom is it?"

Simply because that's the way people talk in everyday life, and I wasn't particularly knowledgeable about grammar.

When I got into my twenties, I learned that—according to the rules of grammar—"to be" takes no object. Yet I still didn't change the way I spoke, because it seemed horribly pretentious and detached from real life.

However, now that I'm older, I feel differently about this. I'm starting to appreciate correct speech and correct grammar more, because I find it more dignified, more polite, and I just like the sound of it more.

Therefore I have found myself saying things like:"It is I!""Who are you?""Is is her!""Who is it?"

As for the popular opinion that "whom" is archaic: I don't agree and, frankly, I don't care. I find "whom" completely natural to use in everyday speech. On the other hand, to me, sentences like: "My friends, all of who I love." just sound like terrible English, and totally jarring.